Effect of microencapsulation using β-cyclodextrin and β-glucan as coating agents on physicochemical properties and phytocannabinoids retention of cannabis flower oil extract

Abstract

Phytocannabinoids possess various biological activities; however, their limited aqueous solubility and poor stability present problems for effective utilization. Encapsulation is a highly effective method to improve the stability and solubility of cannabis extracts. The potential of β-glucan as a coating material for cannabis extract has not been extensively studied. This study aimed to investigate encapsulation of cannabis extracts by freeze-drying using β-glucan or β-cyclodextrin as coating agents. The extract was mixed with coating agent, with core-to-coating ratio of 1:1 and 1:2 (w/w). Tween 20 or 40 % ethanol were employed for preparing emulsion. Characterization was performed using contact angle, SEM, FT-IR, NMR and TGA. Phytocannabinoids and antioxidant properties were analyzed using LC-MS/MS and three antioxidant assays (DPPH, FRAP and ORAC). Results showed that different encapsulation conditions affect the phytocannabinoids contents and their morphology. The microencapsulation with Tween 20 at core-to-coating ratio of 1:1 can retain CBD and THC at 0.19 μg/g oil and 0.04–0.07 μg/g oil. SEM image showed granular structure in β-glucan encapsulated products. FT-IR, NMR and TGA confirmed microencapsulation formation. These microcapsules demonstrated high thermal stability with encapsulation efficiency ranging from 13.38 % to 64.80 %. All microcapsules exhibited various antioxidant activity. This study demonstrates the potential for developing water-soluble cannabinoids for food and pharmaceutical applications.